EP1337393B1 - Method for repairing composite elements - Google Patents

Abstract

The invention relates to a method for repairing composite elements comprising the following structure: (i) 1 - 20 mm metal, (ii) 10 - 300 mm polyisocyanate polyaddition products obtainable by reacting (a) isocyanates (b) compounds which can react against isocyanates, (iii) 1 - 20 mm metal. According to the invention, a section containing (i), (ii) and optionally (iii) is cut from the composite element and removed from the cutting surfaces of the remaining composite element, so that (i) and optionally (iii) extend beyond (ii), when (iii) is removed, by (x) at least 7cms; the cut sections (i) and optionally (iii) are replaced by new layers (ia) and optionally (iiia), and connection occurs with the remaining layers (i) and optionally (iii) of the composite element. Finally, in the space between the layers (i)/(ia) and (iii), and optionally (iii)/(iiia) (a) isocyanates are reacted with (b) isocyanate reactive compounds.

Description

(i)

1 mm bis 20 mm, bevorzugt 2 mm bis 10 mm, besonders bevorzugt 5 mm bis 10 mm Metall,

(ii)

10 mm bis 300 mm, bevorzugt 10 mm bis 100 mm Kunststoffe, bevorzugt Polyisocyanat-Polyadditionsprodukte erhältlich durch Umsetzung von (a) Isocyanaten mit (b) gegenüber Isocyanaten reaktiven Verbindungen,

(iii)

1 mm bis 20 mm, bevorzugt 2 mm bis 10 mm, besonders bevorzugt 5 mm bis 10 mm Metall.

The invention relates to methods for repairing composite elements which have the following layer structure:

(I)

1 mm to 20 mm, preferably 2 mm to 10 mm, particularly preferably 5 mm to 10 mm metal,

(Ii)

10 mm to 300 mm, preferably 10 mm to 100 mm plastics, preferably polyisocyanate polyaddition products obtainable by reacting (a) isocyanates with (b) compounds reactive toward isocyanates,

(Iii)

1 mm to 20 mm, preferably 2 mm to 10 mm, particularly preferably 5 mm to 10 mm metal.

The lengths of the layers (i), (ii) and (iii) relate to the thickness of the respective layer.

For the construction of ships, for example ship hulls and Load compartment covers, bridges, roofs or high-rise buildings must Construction parts are used, the significant loads can withstand external forces. Such construction parts usually consist of these requirements Metal plates or metal supports through an appropriate Geometry or suitable struts are reinforced. So exist Ship hulls of tankers due to increased safety standards usually an inner and an outer Fuselage, each fuselage made of 15 mm thick steel plates that pass through approx. 2 m long steel struts are connected to each other is. Because these steel plates are exposed to considerable forces both the outer and the inner steel shell stiffened by welded-on reinforcement elements. adversely on these classic construction parts substantial amounts of steel that are needed as well the time and labor-intensive production. In addition, such Construction parts on a significant weight, which makes a lower tonnage of the ships and an increased fuel requirement results. In addition, such are classic construction elements on the basis of steel very maintenance-intensive, since both the outer surface, as well as the surfaces of the steel parts between the outer and inner shell regularly against corrosion must be protected.

As a replacement for the steel structures are SPS elements (sandwich plate system) known that a composite of metal and Include plastic. Due to the adhesion of the plastic to the two metal layers create composite elements with extraordinary Advantages over known steel constructions. such PLC elements are known from the documents US-A-6 050 208, US-A-5 778 813, DE-A 198 25 083, DE-A 198 25 085, DE-A 198 25 084, DE-A 198 25 087 and DE-A 198 35 727. In comparison to constructions, which are based exclusively on steel or iron the plc elements when repairing the difficulty on that they contain plastics. Process of repair resulting from the Steel structures are known, so they cannot automatically switch to PLC elements be applied. US-A-6 050 208 discloses methods of Repair of composite elements with a 10 to 300 mm thick arranged between two 2 to 20 mm thick metal outer layers Core layer made of polyisocyanate polyadducts, with a cutout containing a metal and core layer is cut out of the composite element, which are removed on the crotch surfaces of the remaining composite element polyisocyanate polyadducts, the crotch surfaces of the metal layer by a length of extend at least 7cm beyond the core layer.

(i)

1 bis 20 mm, bevorzugt 2 bis 10 mm, besonders bevorzugt 5 bis 10 mm Metall,

(ii)

10 bis 300 mm, bevorzugt 10 bis 100 mm Kunststoffe, bevorzugt Polyisocyanat-Polyadditionsprodukte erhältlich durch Umsetzung von (a) Isocyanaten mit (b) gegenüber Isocyanaten reaktiven Verbindungen,

(iii)

1 bis 20 mm, bevorzugt 2 bis 10 mm, besonders bevorzugt 5 bis 10 mm Metall. Das Reparaturverfahren sollte einfach durchführbar sein und zu Verbundelementen führen, die in ihrer statischen oder mechanischen Belastbarkeit keine wesentlichen Nachteile gegenüber vergleichbaren nicht-reparierten Verbundelementen aufweisen.

The object of the present invention was therefore to develop a method for repairing composite elements which have the following layer structure:

(I)

1 to 20 mm, preferably 2 to 10 mm, particularly preferably 5 to 10 mm metal,

(Ii)

10 to 300 mm, preferably 10 to 100 mm plastics, preferably polyisocyanate polyaddition products obtainable by reacting (a) isocyanates with (b) compounds reactive towards isocyanates,

(Iii)

1 to 20 mm, preferably 2 to 10 mm, particularly preferably 5 to 10 mm metal. The repair process should be simple to carry out and lead to composite elements which, in terms of their static or mechanical resilience, have no significant disadvantages compared to comparable non-repaired composite elements.

This object was achieved by the method according to claim 1, wherein the composite element containing a section (i), (ii) and, if appropriate (iii) cuts out on the cut surfaces of the remaining composite element (ii) removed so that at the Cut surfaces (i) and optionally (iii) if (iii) removed will extend a length (x) of at least 7 cm beyond (ii), the cut layers (i) and optionally (iii) replaced by new layers (ia) and optionally (iiia) and with the remaining layers (i) or, if appropriate (iii) connects the composite element after connecting the Layers (i) with (ia) and optionally (iii) with (iiia) in the between the connected layers (i) / (ia) and (iii) respectively if applicable, (iii) / (iiia) free space, which is not filled by (ii), the starting materials for production of (ii), in particular (a) and (b) and then in the space between layers (i) / (ia) and (iii) respectively optionally (iii) / (iiia) (a) isocyanates with (b) opposite Reacts isocyanate-reactive compounds, the filling the space between (i) / (ia) and (iii) or, if appropriate (iii) / (iiia) with (a) and (b) and optionally the other raw materials with high-pressure machines with axial piston metering is carried out, the storage container with agitator and designed for temperature control and the discharge rate 0.1 to 3.0 kg / sec.

Composite elements that are repaired by the method according to the invention are generally known and can for example via Elastogran GmbH, Germany or Intelligent Engineering Limited, England. Your manufacture and their properties are described in the writings cited at the beginning.

(1) Ausschneiden des schadhaften Abschnitts des Verbundelementes

(2) Entfernen von (ii) zwischen (i) und (iii) an den Schnittkanten des verbleibenden Verbundelementes

(3) Einfügen von neuen Schichten (ia) und gegebenenfalls (iiia), die die ausgeschnittenen Schichten (i) und gegebenenfalls (iii) ersetzen

(4) Verbinden der neuen Schichten (ia) und gegebenenfalls (iiia) mit den Schichten (i) beziehungsweise (iii)

(5) Auffüllen des Raumes zwischen den Schichten (i)/(ia) und (iii) beziehungsweise gegebenenfalls (iiia)/(iii) mit (ii) indem man in dem Raum (a) und (b) füllt, die zu den Polyisocyanat-Polyadditionsprodukten reagieren.

The method according to the invention is thus divided into the following steps:

(1) cutting out the defective portion of the composite member

(2) removing (ii) between (i) and (iii) on the cut edges of the remaining composite member

(3) inserting new layers (ia) and optionally (iiia), which replace the cut layers (i) and optionally (iii)

(4) connecting the new layers (ia) and optionally (iiia) with the layers (i) or (iii)

(5) Filling the space between the layers (i) / (ia) and (iii) or optionally (iiia) / (iii) with (ii) by filling in the space (a) and (b) that correspond to the Polyisocyanate polyadducts react.

Removing the defective portion of the composite element can preferably be done by methods that the composite element do not heat to a temperature higher than the inflammatory or decomposition temperature of (ii). Methods are preferred applied, in which a volume of (ii) of one Cubic centimeters within the most by the cutting process heated area of the composite element over a time interval of one minute on average to a temperature of heated below 180 ° C. Too high a temperature during the cutting process can result in (ii) being destroyed in large areas and so that the stability of the composite element is permanently impaired becomes. Also an uncontrolled ignition of (ii) during the cutting process should be avoided. One is preferred the section containing (i), (ii) and optionally (iii) cut out by sawing or using a laser preferably by sawing, for example using a circular saw, cutting disc preferably with simultaneous cooling (e.g. with water, liquid nitrogen and / or drilling emulsion) or by means of high pressure water jet cutting. Such separation processes are relevant specialist generally known. Preferred are (i) (ii) and (iii) removed, particularly preferably simultaneously in a cutting process. From the composite elements to be repaired For example, round, oval or square sections can be removed so that, for example, the composite element to be repaired has a hole.

In the second step you remove (ii) from the edges that are marked by the cutting out of the defective section has arisen. This removal of (ii) is essential because in a subsequent one Step the new layers (ia) and optionally (iiia) must be connected to (i) or, if appropriate, (iii) and this connection is usually made by welding. The at this would result in heating if (ii) in the immediate vicinity of the weld seam, to an undesirable Cause warming or even inflammation of (ii). The distance of (ii) can be done in such a way that the between (i) and (iii) part of (ii) to be removed by milling or chiseling, for example by means of a chisel, chisel or spatula, where (ii) before and / or upon removal can be heated to soften it. Prefers removal is carried out by milling. So much of is preferred (ii) removes that layers (i) and optionally (iii), insofar as this layer is removed, in each case by the length (x) of reach at least 7 cm beyond (ii).

In the next step, in the section of the composite element, which should be repaired and removed in the first step was added, new layers (ia) and optionally (iiia). These new layers are usually fixed in such a way that the end face of the plate (i) of the composite element on the Front side of the plate (ia) butts and, if necessary, accordingly the end face of the plate (iii) of the composite element on the Face of the plate (iiia). The plates (i) and are preferred optionally (iii) designed such that in the case of the Fixing the plates to each other no major gaps between the plates (i) and (ia) or, if appropriate (iii) and (iiia) occur. The corresponding replacement layers (ia) and optionally (iiia) thus preferably have dimensions from that exactly in the removed section of the composite element fit. A fixation of the layers (ia) and if necessary (iiia) on or in the composite element is by means of conventional devices possible, for example can (ia) and optionally (iiia) by external brackets, on which (ia) and (iiia) for example magnetic, via adhesive, clamps or by welding are fixed, positioned in relation to the composite element become. As shown later, (ia) and / or optionally (iiia) preferably at least one opening (v) through which in a later step (a) and (b) and optionally fills the other starting materials.

The inserted new layers (ia) or if necessary (iiia) are then coated with layers (i) and optionally connected (iii). This connection can using conventional methods, for example by welding. As a method for welding the metal plates all known methods are used, for example fed by laser or by means of an acetylene / oxygen Flame. The compounds of (i) with (ia) and are preferred (iii) with (iiia) so complete that there are no gaps between the metal plates are present, which are then filled with the source components as a leak to a loss of source materials to lead. It is therefore preferred to connect (ia) to (i) and optionally (iiia) with (iii) by welding.

After connecting the layers (i) with (ia) and optionally (iii) with (iiia) is between the connected layers (i) / (ia) and (iii) or optionally (iii) / (iiia) free space that is not filled by (ii). Da (ii) on strength which contributes to the composite elements and the overall construction it is essential that this space be filled with (ii). To do this, as in the manufacture of the individual composite elements that Starting materials for the production of (ii), in particular (a) and (b) filled and implemented in this room.

Preferably, (ia) and / or optionally (iiia) at least an opening (v) through which one (a) and (b) and optionally fills the other raw materials. Preferably (ia) and optionally (iiia) at least two openings (v), i.e. at least one opening (v) for filling and at least one Opening (v) through which the air can escape from the room to be filled can and which can serve as an overflow opening. Prefers is or are the opening (s) in the layer (ia). Prefers one seals the space to be filled with (a) and (b) between (i) / (ia) and (iii) or optionally (iii) / (iiia) with the exception of the opening (s) (s) before filling with (a) and (b). Filling is preferably carried out in such a way that the starting materials (a) and (b) for the preparation of (ii) continuously without interruption in a single step in the space to be filled. Filling the Space between (i) / (ia) and (iii) or, if applicable (iii) / (iiia) with (a) and (b) and optionally the others Starting materials can be preferred with conventional conveyors be carried out continuously, for example with high and Low pressure machines, preferably high pressure machines.

Filling is preferably carried out using a high-pressure machine a mixing head, in which the starting components are mixed, in a single step, preferably injection process. In a single injection process means that the filling of the Space between (i) / (ia) and (iii) or, if applicable (iii) / (iiia) with the starting materials for the preparation of (ii) the full filling is not interrupted. The raw materials are thus preferred in a single shot Pressure in the space between (i) / (ia) and (iii) respectively optionally given (iii) / (iiia). It is therefore preferred to wear the starting materials by means of a high-pressure apparatus Mixing head.

The mixing head is preferred at the opening (v) through which the Entry of the starting materials takes place, fixed, preferably takes place the connection between the mixing head and the opening such that a running out of the raw materials between the mixing head and the metal plate is prevented and the raw materials completely in the space between (i) / (ia) and (iii) respectively if necessary (iii) / (iiia) can be entered. Prefers you fix the mixing head mechanically. It has proven to be beneficial exposed the metal layer not by weight of the mixing head because this load leads to deformation who can lead metal plates. It is therefore particularly preferred the mixing head is attached to a bracket that is independent of (ia), that carries the mixing head. The is particularly preferred Mixing head not worn by (ia), but with (ia) mechanical fixed. Conventional devices can be used as carriers for the mixing head serve where the mixing head can be attached, for example mounts positioned next to or above (i) or (iii) like scaffolding, cranes or the like.

The amounts of starting materials for the production of (ii) are only difficult to measure so that just the space to be filled is filled, but overflow is prevented. That is why preferably a larger amount of starting components for production from (ii) into the space between (i) / (ia) and (iii) respectively optionally given (iii) / (iiia) as this recording can. The resulting overflow is preferred over at least one of the openings (v) removed. You can preferably on the or attach the overflow vessels to the openings (v) that serve as the overflow. These overflow vessels are preferably located in one Position above that between (i) and (iii) with the starting materials for the production of (ii) space to be filled. This offers the Advantage that only after completely filling with the starting materials an increase in the still liquid, i.e. have not yet reacted Starting materials found in the overflow vessels can be. At the rise in the starting components in the overflow vessels you can thus completely fill the room determine between (i) and (iii), then the overflow vessels seal, for example with a plastic or metal plug preferably with a screw cap that either in the overflow vessel or preferably between the overflow vessel and (ia) and / or (iiia). The opening (v) through which the starting components (a) and (b) are filled remain preferred until the end of the curing process of the mixture (a) and (b) locked the fixed mixing head.

(I) / (ia) and possibly (iii) / (iiia) are not found in a horizontal alignment when filling the room with the starting components, there is preferably at least one an opening (v) in (ia) at the top of (ia) to allow an overflow of starting components from this opening (v) only then takes place when the space to be filled is completely filled.

The openings (v) are preferably bores with a diameter of 0.1 cm to 5.0 cm, preferably 0.5 cm to 4 cm preferred in (ia).

The delivery rate can depend on the volume to be filled can be varied. To ensure a homogeneous curing of (ii) ensure, the delivery rate and funding facility is such chosen that the space to be filled within 0.5 to Be filled for 20 minutes with the components for the preparation of (ii) can. The machines for filling with the Output components for high pressure machines with axial piston metering, the storage container with agitator and temperature controlled is designed and preferably a circuit storage container-mixing head storage container is present, the discharge performance 0.1 to 3.0 kg / sec. Suitable funding facilities are for example high pressure metering systems from Elastogran GmbH, e.g. Puromat®PU 30 for discharge rates from 50 to 600 g / sec or Puromat®PU 150 for discharge rates from 300 to 2800 g / sec.

The starting components are usually at a temperature from 0 to 100 ° C, preferably from 20 to 60 ° C, mixed and like already introduced into the space between (i) and (iii). The mixing can be done mechanically using a stirrer or a stirrer screw, but preferably by the high pressure machines The usual countercurrent principle takes place with the A and B component jet in the mixing head under high pressure hit and mix, taking the beam of each component can also be divided. The reaction temperature, i.e. the temperature, during the reaction is usually> 20 ° C, preferably 50 to 150 ° C.

Individual steps of the repair method according to the invention are shown schematically in Figures 1 to 3. The Removing the damaged section is shown in Figure 1, 1a and 1b shown, the removal of (ii) in Figure 2 or 2a, the insertion of (ia) and optionally (iiia) in Figure 3 or 3a. The repaired Composite elements with the newly manufactured (ii) are in Figures 4 and 4a outlined.

The reaction products (ii) adhere to both (i) and (iii) as also on (ia) and (iiia). This ensures that the connected Gasamtelement has a strength that is almost identical is with the strength of individual, prefabricated composite elements.

In this document, the terms "starting materials" or "Starting components" in particular with respect to (a) isocyanates and (b) To understand isocyanate-reactive compounds, but if necessary, insofar as they are used, also (c) gases, (d) Catalysts, (e) auxiliaries and / or (f) blowing agents.

The reaction of (a) with (b) is preferably carried out in the presence from 1 to 50% by volume of gases (c). It is preferred to use (b) polymer polyols. The reaction of (a) is preferably carried out with (b) in the presence of (f) blowing agents.

(i)

2 mm bis 20 mm, bevorzugt 2 mm bis 10 mm, besonders bevorzugt 5 mm bis 10 mm Metall,

(ii)

10 mm bis 300 mm, bevorzugt 10 mm bis 100 mm Kunststoffe, bevorzugt Polyisocyanat-Polyadditionsprodukte mit einer Dichte von 350 bis 1200 kg/m³ erhältlich durch Umsetzung von (a) Isocyanaten mit (b) gegenüber Isocyanaten reaktiven Verbindungen bevorzugt in Gegenwart von (f) Treibmitteln und/oder 1 bis 50 Volumen-%, bezogen auf das Volumen der Polyisocyanat-Polyadditionsprodukte, mindestens eines Gases (c) sowie gegebenenfalls (d) Katalysatoren und/oder (e) Hilfsmittel,

(iii)

2 mm bis 20 mm, bevorzugt 2 mm bis 100 mm, besonders bevorzugt 5 mm bis 10 mm Metall.

The composite elements preferably have the following layer structure:

(I)

2 mm to 20 mm, preferably 2 mm to 10 mm, particularly preferably 5 mm to 10 mm metal,

(Ii)

10 mm to 300 mm, preferably 10 mm to 100 mm plastics, preferably polyisocyanate polyadducts with a density of 350 to 1200 kg / m ³ obtainable by reacting (a) isocyanates with (b) compounds reactive toward isocyanates, preferably in the presence of ( f) blowing agents and / or 1 to 50% by volume, based on the volume of the polyisocyanate polyadducts, of at least one gas (c) and optionally (d) catalysts and / or (e) auxiliaries,

(Iii)

2 mm to 20 mm, preferably 2 mm to 100 mm, particularly preferably 5 mm to 10 mm metal.

The polyisocyanate polyadducts (ii) according to the invention Composite elements produced preferably have a modulus of elasticity from> 275 MPa in the temperature range from -45 to + 50 ° C (after DIN 53457), an adhesion to (i) and (iii) of> 4 MPa (according to DIN 53530), an elongation of> 30% in the temperature range of -45 up to + 50 ° C (according to DIN 53504), a tensile strength of> 20 MPa (according to DIN 53504) and a compressive strength of> 20 MPa (according to DIN 53421) on.

The composite elements according to the invention can be produced perform such that one between (i) and (iii) polyisocyanate polyadducts (ii), usually polyurethanes, optionally Have urea and / or isocyanurate structures can, by reacting (a) isocyanates with (b) Isocyanate-reactive compounds, if appropriate in the presence of blowing agents (f), 1 to 50% by volume, based on the volume the polyisocyanate polyadducts, at least one gas (c), (d) produces catalysts and / or (e) auxiliaries, where preferably (ii) adheres to (i) and (iii).

The reaction is preferably carried out in a closed form, i.e. (i) and (iii) are filled with the Starting components for the production of (ii) in a form which locked after complete entry of the starting components becomes. After the implementation of the starting components for Production of (ii) the composite element can be removed from the mold.

The surfaces of (i), (ia), (iii) and (iiia) are before Production of composite elements for cleaning and increasing the Surface roughness with sand or steel balls preferred with Blasted corundum or iron gravel.

This blasting can be done using the usual methods at where the blasting material, for example, under high pressure on the Surfaces.

Suitable equipment for such treatment is commercial available.

By treating the surfaces after the implementation of (a) with (b) in contact with (ii) leads to one clearly improved liability of (ii) to (i) / (ia) and (iii) respectively optionally (iii) / (iiia). The surfaces of (i) / (ia) and (iii) or, if applicable, to (ii) should adhere, are preferably free of inorganic and / or organic Substances that reduce liability, for example Dust, dirt, oils and greases or generally as mold release agents known fabrics.

Layers (i), (ia), (iii) and optionally (iiia) can preferably as conventional metal plates, for example iron, Steel, copper and / or aluminum plates, with the invention Thicknesses can be used. (I) and (ia) are preferably based on the same metal so that joining the layers for example is simplified by welding. So far too (iii) is removed, the same applies to layers (iii) and (Iiia).

Filling the space between (i) / (ia) and (iii) respectively optionally (iii) / (iiia) can be in both vertical and also horizontal alignment of (i) / (ia) and (iii) respectively optionally (iii) / (iiia).

Both (i) / (ia) and (iii) / (iiia) can be coated, for example primed, painted and / or with common plastics coated in the production of the composite elements according to the invention be used. (I) / (ia) and (iii) / (iiia) uncoated and particularly preferably for example used cleaned by conventional sandblasting.

The production of the polyisocyanate polyadducts (ii), usually polyurethane and optionally polyisocyanurate products, especially polyurethane elastomers, by reaction of (a) isocyanates with (b) isocyanate-reactive Compounds optionally in the presence of (f) blowing agents, (d) Catalysts (e) auxiliaries and / or (c) gases is common have been described.

The starting materials (a), (b), (c), (d), (e) and (f) in the inventive Methods are described below as examples:

Suitable isocyanates (a) are the aliphatic, known per se, cycloaliphatic, araliphatic and / or aromatic isocyanates, preferred diisocyanates in question, if necessary after generally known methods biuretized and / or isocyanurated may have been. The following are examples: Alkylene diisocyanates with 4 to 12 carbon atoms in Alkylene radical, such as 1,12-dodecane diisocyanate, 2-ethyl-tetramethylene-1,4-diisocyanate, 2-methylpentamethylene diisocyanate-1.5, tetramethylene diisocyanate-1.4, Lysine ester diisocyanates (LDI), 1,6-hexamethylene diisocyanate (HDI), cyclohexane-1,3- and / or 1,4-diisocyanate, 2,4- and 2,6-hexahydrotoluenediisocyanate and the corresponding mixtures of isomers, 4,4'-, 2,2'- and 2,4'-dicyclohexylmethane diisocyanate and the corresponding isomer mixtures, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI), 2,4- and / or 2,6-tolylene diisocyanate (TDI), 4,4'-, 2,4'- and / or 2,2'-diphenylmethane diisocyanate (MDI), polyphenylpolymethylene polyisocyanates and / or mixtures containing at least two of the isocyanates mentioned. In addition, ester, urea, Allophanate, carbodiimide, uretdione and / or urethane groups containing Di- and / or polyisocyanates in the invention Procedures are used. 2,4'-, 2,2'- and / or 4,4'-MDI and / or polyphenylpolymethylene polyisocyanates are preferably used, Mixtures containing polyphenylpolymethylene polyisocyanates are particularly preferred and at least one of the MDI isomers.

As (b) isocyanate-reactive compounds, for example Connections are used that are opposite Isocyanate reactive groups hydroxyl, thiol and / or primary and / or have secondary amino groups and usually a Have molecular weights from 60 to 10000 g / mol, e.g. polyols selected from the group of polymer polyols, polyether polyalcohols, Polyester polyalcohols, polythioether polyols, hydroxyl-containing Polyacetal and hydroxyl-containing aliphatic Polycarbonates or mixtures of at least two of the mentioned polyols. These compounds usually have one Functionality towards isocyanates from 2 to 6 and a molecular weight from 400 to 8000 and are general to the expert known.

For example, come as polyether polyalcohols, which according to known Technology by adding alkylene oxides, for example Tetrahydrofuran, 1,3-propylene oxide, 1,2- or 2,3-butylene oxide, Styrene oxide and preferably ethylene oxide and / or 1,2-propylene oxide are available on usual starter substances. As starter substances For example, known aliphatic, araliphatic, cycloaliphatic and / or aromatic compounds are used, the at least one, preferably 2 to 4 Hydroxyl groups and / or at least one, preferably 2 to 4 amino groups contain. For example, as starter substances Ethanediol, diethylene glycol, 1,2- or 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, glycerin, Trimethylolpropane, neopentyl glycol, sugar, for example Sucrose, pentaerythritol, sorbitol, ethylenediamine, propanediamine, Neopentanediamine, hexamethylenediamine, isophoronediamine, 4,4'-diaminodicyclohexylmethane, 2- (ethylamino) ethylamine, 3- (methylamino) propylamine, Diethylenetriamine, dipropylenetriamine and / or N, N'-bis (3-aminopropyl) ethylenediamine can be used.

The alkylene oxides can be individually, alternately in succession or can be used as mixtures. Alkylene oxides are preferred used which lead to primary hydroxyl groups in the polyol. Particularly preferred polyols are those which are used for Completion of the alkoxylation were alkoxylated with ethylene oxide and thus have primary hydroxyl groups.

As polymer polyols, a special class of polyether polyols, can be compounds generally known from polyurethane chemistry are used, preferably styrene-acrylonitrile graft polyols.

Especially the use of polymer polyols can shrink the Polyisocyanate polyaddition product, for example polyurethane reduce significantly and thus to an improved liability from (ii) to (i) and (iii). If necessary, as another Measures to reduce shrinkage prefer blowing agents (f) and / or gases (c) are used.

Suitable polyester polyols can, for example, from organic Dicarboxylic acids with 2 to 12 carbon atoms, preferably aliphatic Dicarboxylic acids with 4 to 6 carbon atoms, and polyhydric alcohols, preferably diols, with 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms become. The polyester polyols preferably have functionality from 2 to 4, in particular 2 to 3, and a molecular weight from 480 to 3000, preferably 600 to 2000 and in particular 600 to 1500.

The composite elements according to the invention are preferably used of polyether polyalcohols as component (b) for the reaction prepared with the isocyanates, expediently such with an average functionality compared to isocyanates of 1.5 to 8, preferably 2 to 6, and a molecular weight of 400 to 8000th

The use of polyether polyalcohols offers considerable advantages through improved stability of the polyisocyanate polyaddition products against hydrolytic cleavage and due to the lower viscosity, in each case in comparison with polyester polyalcohols. The improved stability against hydrolysis is particularly advantageous when used in shipbuilding. The lesser Viscosity of the polyether polyalcohols and the reaction mixture for the production of (ii) containing the polyether polyalcohols enables faster and easier filling of the room between (i) and (iii) with the reaction mixture for preparation of the composite elements. Because of the considerable dimensions Construction parts in shipbuilding in particular are low-viscosity Liquids are a great advantage.

Other compounds which are reactive toward isocyanates are Suitable substances that have a hydrocarbon structure with 10 to 40 carbon atoms and 2 to 4 reactive towards isocyanates Have groups. Under the term hydrocarbon skeleton understand an uninterrupted sequence of carbon atoms which is not, for example, in the case of ethers with oxygen atoms is interrupted. As such substances, also below referred to as (b3), for example castor oil and their Derivatives are used.

Furthermore, as compounds which are reactive toward isocyanates in addition to the compounds mentioned with a conventional one Molecular weight of 400 to 8000 optionally diols and / or Triols with molecular weights from 60 to <400 as chain extensions and / or crosslinking agents in the inventive Procedures are used. To modify the mechanical Properties, e.g. the hardness, however, the addition of Chain extenders, crosslinking agents or, if appropriate mixtures of these also prove to be advantageous. The chain extension and / or crosslinking agents preferably have Molecular weight from 60 to 300. Consider for example aliphatic, cycloaliphatic and / or araliphatic Diols with 2 to 14, preferably 4 to 10 carbon atoms, such as. Ethylene glycol, 1,3-propanediol, 1,10-decanediol, o-, m-, p-dihydroxycyclohexane, diethylene glycol, dipropylene glycol and preferably 1,4-butanediol, 1,6-hexanediol and bis (2-hydroxyethyl) hydroquinone, Triols, such as 1,2,4-, 1,3,5-trihydroxycyclohexane, Glycerin and trimethylolpropane, low molecular weight hydroxyl groups Polyalkylene oxides based on ethylene and / or 1,2-propylene oxide and the aforementioned diols and / or triols as Starter molecules and / or diamines such as e.g. diethyltoluenediamine and / or 3,5-dimethylthio-2,4-toluenediamine.

If so for the production of the polyisocyanate polyaddition products Chain extenders, crosslinking agents or mixtures thereof Find application, they come conveniently in one Amount from 0 to 30% by weight, preferably from 1 to 30% by weight, based on the weight of the total isocyanates used reactive compounds (b).

In addition, as (b) aliphatic, araliphatic, cycloaliphatic and / or aromatic carboxylic acids to optimize the Hardening course used in the production of (ii). Examples of such carboxylic acids are formic acid, acetic acid, Succinic acid, oxalic acid, malonic acid, glutaric acid, adipic acid, Citric acid, benzoic acid, salicylic acid, phenylacetic acid, Phthalic acid, toluenesulfonic acid, derivatives of the acids mentioned, Isomers of the acids mentioned and any mixtures of the above Acids. The weight fraction of these acids can be 0 to 5 wt .-%, preferably 0.2 to 2 wt .-%, based on the total weight of (b).

With the use of amine-started polyether polyalcohols also the hardening behavior of the reaction mixture for production of (ii) can be improved. The compounds are preferred (b), like the other components for the production of (ii) used with the lowest possible water content, to the formation of carbon dioxide by reaction of the water with Avoid isocyanate groups.

The preferred use of polymer polyols, in particular styrene-acrylonitrile graft polyols, can shrink the polyisocyanate polyaddition product, for example, the polyurethane decrease and thus to an improved liability of (ii) (i) and (iii) lead. If necessary, as further measures, to reduce the shrinkage, blowing agents (f) and / or gases (c) are preferably used.

As component (c) for the preparation of (ii), generally known Compounds are used that have a boiling point a pressure of 1 bar of less (i.e. at lower temperatures than) -50 ° C, for example air, carbon dioxide, Nitrogen, helium and / or neon. Air is preferably used. Component (c) is preferred over component (a), particularly preferably inert towards components (a) and (b), i.e. reactivity of the gas towards (a) and (b) is hardly preferably not to be demonstrated. The use of gas (c) differs fundamentally different from the use of conventional blowing agents for the production of foamed polyurethanes. While usual Blowing agents (f) are used in liquid form or in the case of gaseous ones physical blowing agent in the polyol component are soluble to a small extent) and during the implementation either evaporate due to heat or but in the case of water due to the reaction with the isocyanate groups Gaseous carbon dioxide is developed in the In the present invention, component (c) is preferably already gaseous used as an aerosol, for example in the polyol component.

Well-known compounds can be used as catalysts (d) be the opposite of the reaction of isocyanates with the Accelerate isocyanate-reactive compounds strongly, whereby preferably a total catalyst content of 0.001 to 15% by weight, in particular 0.05 to 6% by weight, based on the weight of the total isocyanate reactive Connections, is used. For example, the following Compounds are used: triethylamine, tributylamine, Dimethylbenzylamine, dicyclohexylmethylamine, dimethylcyclohexylamine, N, N, N ', N'-tetramethyl-diamino-diethyl ether, bis (dimethylaminopropyl) urea, N-methyl- or N-ethylmorpholine, N-cyclohexylmorpholine, N, N, N ', N'-tetramethylethylene diamine, N, N, N', N'-tetramethyl butane diamine, N, N, N ', N'-tetramethylhexanediamine-1,6, Pentamethyldiethylenetriamine, dimethylpiperazine, N-dimethylaminoethylpiperidine, 1,2-dimethylimidazole, 1-azabicyclo- (2,2,0) -octane, 1,4-diazabicyclo- (2,2,2) octane (Dabco) and alkanolamine compounds, such as triethanolamine, triisopropanolamine, N-methyl and N-ethyl-diethanolamine, dimethylaminoethanol, 2- (N, N-dimethylaminoethoxy) ethanol, N, N ', N' '- tris (dialkylaminoalkyl) hexahydrotriazines, e.g. N, N ', N' '- tris (dimethylaminopropyl) -s-hexahydrotriazine, Iron (II) chloride, zinc chloride, lead octoate and preferably Tin salts such as tin dioctoate, tin diethylhexoate, dibutyltin dilaurate and / or dibutyldilauryltin mercaptide, 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, Tetraalkylammonium hydroxides, such as tetramethylammonium hydroxide, Alkali hydroxides, such as sodium hydroxide, Alkaline alcoholates, such as sodium methylate and potassium isopropylate, and / or alkali metal salts of long-chain fatty acids with 10 to 20 carbon atoms and optionally pendant OH groups.

It has proven to be very advantageous to manufacture (ii) in the presence of (d) to accelerate the reaction.

The reaction mixture for the production of the polyisocyanate polyadducts (ii) Optionally, (e) auxiliaries can be incorporated become. Examples include fillers, surface-active Substances, dyes, pigments, flame retardants, Hydrolysis inhibitor, fungistatic, bacteriostatic acting substances and foam stabilizers.

Suitable surface-active substances include Connections into consideration which support the homogenization of the raw materials serve and are also suitable, if appropriate, the Regulate structure of plastics. For example Emulsifiers, such as the sodium salts of castor oil sulfates or of fatty acids and salts of fatty acids with amines, e.g. oleic acid diethylamine, stearic acid diethanolamine, ricinoleic acid Diethanolamine, salts of sulfonic acids, e.g. Alkali or ammonium salts of dodecylbenzene or dinaphthylmethane disulfonic acid and ricinoleic acid. The surface-active substances are usually in amounts of 0.01 to 5% by weight, based on 100% by weight of the total isocyanate reactive Compounds (b) applied.

Suitable flame retardants are, for example, tricresyl phosphate, Tris (2-chloroethyl) phosphate, tris (2-chloropropyl) phosphate, Tris (1,3-dichloropropyl) phosphate, tris (2,3-dibromopropyl) phosphate, Tetrakis (2-chloroethyl) ethylene diphosphate, dimethyl methane phosphonate, Diethanolaminomethylphosphonsäurediethylester and commercially available halogen-containing flame retardant polyols. Except for those already Halogen-substituted phosphates mentioned can also be inorganic or organic flame retardants such as red phosphorus, Alumina hydrate, antimony trioxide, arsenic oxide, ammonium polyphosphate and calcium sulfate, expandable graphite or cyanuric acid derivatives, such as. Melamine, or mixtures of at least two flame retardants, such as. Ammonium polyphosphates and melamine as well optionally corn starch or ammonium polyphosphate, melamine and Expandable graphite and / or optionally aromatic polyester for Flame-proofing of the polyisocyanate polyaddition products used become. In general, it has proven useful to 5 to 50% by weight, preferably 5 to 25% by weight, of the flame retardants mentioned, based on the weight of the total used compounds reactive towards isocyanates.

As fillers, in particular reinforcing fillers, are the known, conventional organic and inorganic Fillers, reinforcing agents, weighting agents, agents to improve the abrasion behavior in paints, coating agents etc. to understand. In particular, are exemplary called: inorganic fillers such as silicate minerals, for example layered silicates such as antigorite, serpentine, Hornblende, Amphibole, Chrisotil and Talc, metal oxides, like Kaolin, aluminum oxides, titanium oxides and iron oxides, metal salts, such as chalk, heavy spar and inorganic pigments such as cadmium sulfide and zinc sulfide, and glass and others. Preferably used are kaolin (china clay), aluminum silicate and coprecipitates made of barium sulfate and aluminum silicate as well as natural and synthetic fibrous minerals such as wollastonite, metal and Glass fibers of short length. Coming as organic fillers for example: coal, melamine, rosin, cyclopentadienyl resins and graft polymers and cellulose fibers, Polyamide, polyacrylonitrile, polyurethane, polyester fibers based on aromatic and / or aliphatic dicarboxylic acid esters and especially carbon fibers. The inorganic and organic fillers can be used individually or as mixtures become.

Preferably, 10 to 70% by weight is used in the preparation of (ii) Fillers, based on the weight of (ii), as (e) auxiliaries on. The fillers used are preferably talc, kaolin, calcium carbonate, Heavy spar, glass fibers and / or micro glass balls. The size of the particles of the fillers should preferably be chosen so that that the registration of the components for the preparation of (ii) in the Space between (i) and (iii) is not obstructed. Especially the fillers preferably have particle sizes of <0.5 mm.

The fillers are preferably mixed with the polyol component in the implementation for the production of the polyisocyanate polyadducts used.

The fillers can be used in comparison, for example greater thermal expansion coefficient than steel To reduce polyisocyanate polyadducts and thus the of the steel. This for a sustainable, firm network between layers (i), (ii) and (iii) is particularly advantageous, because this reduces the stresses between the layers when thermal Stress occur.

Preferred foam stabilizers for the production of (ii) as (e) are preferred used, the commercially available and the Are generally known to a person skilled in the art, for example generally known Polysiloxane-polyoxyalkylene block copolymers, e.g. Tegostab 2219 from the Goldschmidt company. The proportion of these foam stabilizers in the preparation of (ii) is preferably 0.001 to 10% by weight, particularly preferably 0.01 to 10% by weight, in particular 0.01 to 2 wt .-%, based on the weight of the preparation of (ii) components (b), (e) and optionally (D). The use of these foam stabilizers causes the Component (c) in the reaction mixture for the preparation of (ii) is stabilized.

In general, polyurethane chemistry can be used as blowing agent (f) known blowing agents are used, for example physical and / or chemical blowing agents. Such physical Blowing agents generally have a boiling point at one Pressure of 1 bar of greater (i.e. at temperatures higher than) -50 ° C. Examples of physical blowing agents are e.g. CFCs, HCFC, HFC, aliphatic hydrocarbons, cycloaliphatic Hydrocarbons, each with for example 4 to 6 carbon atoms or mixtures of these substances, for example trichlorofluoromethane (Boiling point 24 ° C), chlorodifluoromethane (boiling point -40.8 ° C), dichlorofluoroethane (boiling point 32 ° C), chlorodifluoroethane (Boiling point -9.2 ° C), dichlorotrifluoroethane (boiling point 27.1 ° C), Tetrafluoroethane (boiling point -26.5 ° C), hexafluorobutane (boiling point 24.6 ° C), iso-pentane (boiling point 28 ° C), n-pentane (boiling point 36 ° C), Cyclopentane (boiling point 49 ° C).

As a chemical blowing agent, i.e. Propellant due to a Reaction, for example with isocyanate groups, gaseous products form, come for example water, hydrate water-containing Compounds, carboxylic acids, tertiary alcohols, e.g. t-butanol, carbamates, for example those in EP-A 1000955, in particular on pages 2, lines 5 to 31 and page 3, lines 21 to 42 describe carbamates, carbonates, e.g. ammonium carbonate and / or ammonium hydrogen carbonate and / or guanidine carbamate in Consideration.

Preferred blowing agents (f) are water and / or carbamates used.

The blowing agents (f) are preferably used in an amount sufficient to obtain the preferred density of (ii). This can be done with simple routine experiments that the skilled person are generally known. Particularly preferred the blowing agents (f) in an amount of 0.05 to 10 wt .-%, in particular from 0.1 to 5% by weight, in each case based on the total weight of the polyisocyanate polyadducts used.

The weight of (ii) by definition corresponds to the weight of the for the production of (ii) components (a), (b) and (c) and optionally (d) and / or (e).

For the production of the polyisocyanate polyaddition products according to the invention are the isocyanates and the isocyanates implemented reactive compounds in such amounts, that the equivalence ratio of NCO groups of the isocyanates (a) to the sum of the reactive hydrogen atoms towards isocyanates reactive compounds (b) and optionally (f) 0.85 to 1.25: 1, preferably 0.95 to 1.15: 1 and in particular 1 to 1.05: 1. If (ii) at least partially isocyanurate groups usually contains a ratio of NCO groups to the sum of the reactive hydrogen atoms from 1.5 to 60: 1, preferably 1.5 to 8: 1, applied.

The polyisocyanate polyadducts are usually made after the one shot process or the prepolymer process, for example with the help of high pressure or low pressure technology manufactured.

It has proven particularly advantageous to use the two-component process to work and the isocyanates reactive compounds (b), optionally the blowing agents (f) and optionally the catalysts (d) and / or auxiliaries (e) to combine in component (A) (polyol component) and preferred to mix intimately with one another and as component (B) To use isocyanates (a).

Component (c) can contain the reaction mixture containing (a), (b) and optionally (f), (d) and / or (e), and / or the individual components (a), (b) already described, (A) and / or (B). The component that is mixed with (c) is usually liquid. The components are preferred mixed into component (b).

The mixing of the corresponding component with (c) can generally known methods. For example, (c) by well-known loading devices, for example Air loading devices, preferably under pressure, for example compressed from a pressure vessel or by a compressor, e.g. can be supplied through a nozzle to the corresponding component. The corresponding mixture is preferably thoroughly mixed Components with (c) so that gas bubbles from (c) in the usually liquid component preferably a size of 0.0001 to 10, particularly preferably 0.0001 to 1 mm.

The content of (c) in the reaction mixture for the production of (ii) can generally in the return line of the high pressure machine known measuring devices on the density of the reaction mixture be determined. The content of (c) in the reaction mixture can preferred based on a control unit automatically this density can be regulated. The component density can be during the usual circulation of the material in the machine too determined online at very low circulation speed and be regulated.

The composite elements obtainable according to the invention are used especially in areas where construction elements are required that can withstand great forces, for example as Construction parts in shipbuilding, e.g. in ship hulls, for example Double hulls with one outer and one inner Wall, and cargo space covers, cargo space partitions, loading flaps or in buildings, for example bridges or as construction elements in house building, especially in high-rise buildings.

The composite elements according to the invention are not classic Confuse sandwich elements that have a polyurethane and / or core Contain rigid polyisocyanurate foam and usually be used for thermal insulation. such known sandwich elements would be comparative due to their lower mechanical strength not for the above Suitable areas of application.

Compact polyisocyanate polyadducts, i.e. Products that are not from a network of gas-filled cells, which are connected to each other via webs and cell walls.

The width and length of the composite elements can usually 0.5 to 10 m, preferably 1 m to 5 m.

Claims (7)

1. A process for repairing composite elements which have the following layer structure:

   (i)

   from 1 to 20 mm of metal,

   (ii)

   from 10 to 300 mm of polyisocyanate polyaddition products obtainable by reacting (a) isocyanates with (b) compounds reactive toward isocyanates,

   (iii)

   from 1 to 20 mm of metal,

   which comprises cutting out from the composite element a section comprising (i), (ii) and, where appropriate, (iii), removing (ii) at the cut surfaces of the remaining composite element so that (i) and, where appropriate, (iii), if (iii) is removed, protrude by a length (x) of at least 7 cm over (ii), replacing the layers (i) and, where appropriate, (iii) which have been cut out with new layers (ia) and, where appropriate, (iiia), and bonding these to the remaining layers (i) and, where appropriate, (iii) of the composite element, and, after the bonding of the layers (i) to (ia), and, where appropriate, (iii) to (iiia), the starting materials for preparing (ii), in particular (a) and (b), are charged to the unoccupied space not filled by (ii) located between the bonded layers (i)/(ia) and (iii), or, where appropriate, (iii)/(iiia), and then reacting (a) isocyanates with (b) compounds reactive toward isocyanates in the space between the layers (i)/(ia) and (iii) or, where appropriate, (iii)/(iiia), where high-pressure machinery using axial piston metering is used to introduce (a) and (b), and also, where appropriate, the other starting materials into the space between (i)/(ia) and (iii) or, where appropriate, (iii)/(iiia), and where the feed vessel has a stirrer and is temperature-controllable, and the discharge rate is from 0.1 to 3.0 kg/sec.
2. A process as claimed in claim 1, where the section comprising (i), (ii) and, where appropriate, (iii) is cut out by sawing or by means of a laser.
3. A process as claimed in claim 1, where welding is used to bond (ia) to (i) and, where appropriate, (iiia) to (iii).
4. A process as claimed in claim 3, where the space between (i)/(ia) and (iii)/where appropriate (iiia) to be filled with (a) and (b) is sealed off, except for openings (v) prior to filling with (a) and (b).
5. A process as claimed in claim 1, where the starting materials (a) and (b) for preparing (ii) are introduced continuously without interruption, in a single operation, into the space to be filled between (i)/(ia) and (iii)/where appropriate (iiia).
6. A process as claimed in claim 5, where the starting materials are introduced by means of a high-pressure apparatus, by way of a mixing head.
7. A process as claimed in claim 6, where the mixing head is mechanically or magnetically secured to the opening in (ia) or (iiia), through which the starting materials are introduced.

Images